Tunnels, walls and roofs are subject to continuous heavy soiling owing to the vehicles travelling through the tunnel, and therefore cleaning measures are required at regular intervals.
Devices of the type mentioned at the outset, which are used for surface cleaning on light railways as a key element in maintenance measures, are suitable for this purpose. As a result of the increasing soiling of railway facilities owing to waste, but also owing to brake sand, dust and metal particles abraded from the rails, measures must increasingly be taken to solve the problem of surface cleaning and thus improve not only the outward appearance of the railway facilities but also the resilience of the ballasted track by reducing soiling.
In these cleaning solutions, the dust-laden air is cleaned by means of either dry or wet filters. Solutions of this type often do not provide the desired effect when impurities caught between the ballast stones are not carried along with the suction flow.
WO 2010/075828 A1 also discloses a device for cleaning tunnel walls and tunnel roofs and for aspirating and cleaning ballast substructures, in which device a vortex which is immanent in the cleaning region and which provides the overpressure curtain required for operation is produced by inclining the air nozzles. In this case, the dirt particles which are loosened or released are drawn into the suction body specifically owing to the inclined position of the air nozzles.
DE 92 03 164 U1 further relates to a device for cleaning the rail track, which device can be fitted on a rail or multiway vehicle and comprises a lowerable suction box and at least one compressed-air nozzle in the suction box, the suction box and the compressed-air nozzle being connected to a suction unit and a compressor which are arranged on the vehicle.
DE 1 244 221 B discloses a device for cleaning points or rails, which device can be installed on a motor vehicle and comprises two nozzle boxes which are mounted on a trolley and can be moved thereby along the rails. A suction nozzle is arranged approximately centrally in each nozzle box and is connected to a boiler of the vehicle via a flexible hose. A suction box which extends laterally beyond the two rails has a plurality of compressed-air nozzles made of resilient material distributed over its entire width.
In practice, it has proven disadvantageous that the aspiration can result in turbulent mixing of the supplied compressed air with the air deflected from the surface and containing the dirt particles. In particular during cleaning of the track bed, during which the compressed-air jet impinges not on substantially planar surfaces but on a complex topography, the resulting swirls can impact on the cleaning power.